What are the 4 types of passive bloodstains?
Passive bloodstains can be further subdivided to include drops, drip patterns, pools, and clots.
- Passive Bloodstain. Passive Bloodstain on a rough surface (such as wood or concrete)
- Projected Bloodstain. Projected Bloodstain, possibly a Cast-Off Pattern or a HVIS.
- Transfer Bloodstain.
What type of blood spatter would a gunshot produce?
Gunshot injuries -‐ mist-‐like spatter caused by bullets entering and exiting the body. When blood is impacted, droplets are dispersed through the air. When these droplets strike a surface, the shape of the stain changes depending on the angle of impact, velocity, distance travelled and type of surface impacted.
What is an Expirated blood pattern?
Term. Expirated Blood Pattern. Definition. A pattern created by blood that is expelled out of the nose, mouth, or respiratory system as a result of air pressure and/or airflow.
What is a transfer bloodstain?
Background: A transfer bloodstain is created when a wet, bloody surface comes in contact with a secondary surface. A recognizable image of all, or a portion, of the original surface may be observed in the pattern, as in the case of a bloody hand or footwear.
What is a satellite drop of blood?
Satellite Spatter — Small droplets of blood that are distributed around a drop or pool of blood as a result of the blood impacting the target surface. Spatter — That blood which has been dispersed as a result of force applied to a source of blood.
What is the difference between the point of convergence and the point of origin?
The source of blood spatter can be localized by following the direction of travel of several stains. What is the difference between the point of origin and point of convergence? Point of origin is in 3D space, point of convergence is in 2D space. Passive – no force applied to blood other than gravity.
How do you find the point of origin?
By measuring the width and length of a single drop of blood, the angle of impact can be assessed. By using the Law of Tangents, the height from which the blood fell, or the point of origin for the blood, can be calculated. Contains one 90-degree angle.
What does the tail of a blood drop tell you?
The direction of blood droplets can be determined from the shape that it forms when they hit the flat surface. The tail of the elongated drop points to the travel direction. blood droplet that looks like this may have been caused by a blunt object and is called a projected bloodstain.
What does the angle of impact tell us?
By measuring the width and length of the stain, the angle of impact can be calculated, helping investigators determine the actions that may have taken place at the scene. As the angle of impact changes, so does the appearance of the resulting stain.
What is the sine of the blood drop’s angle of impact?
The width divided by the length equals 0.5. The ArcSin of 0.5 is 30, meaning the blood hit the surface at a 30-degree angle. In a bloodstain measuring 0.04 by 0.16 inches (1 by 4 millimeters), the impact angle comes out to about 14.5 degrees.
What two forces act on a falling drop of blood?
The spherical shape is caused by the surface tension of the blood. Surface Tension causes the blood drop to pull itself in; both horizontally and vertically. The blood drop will settle into a spherical shape, as a result of the surface tension.
How do you calculate the impact angle of blood spatter?
Angle of Impact
- Measure the length and width of the splatter.
- Divide the width of the splatter by its length.
- Determine the arcsin of that number, typically using a calculator with an arcsin function.
How do you analyze blood spatter?
Bloodstain Pattern Analysis
- Where did the blood come from?
- What caused the wounds?
- From what direction was the victim wounded?
- How were the victim(s) and perpetrator(s) positioned?
- What movements were made after the bloodshed?
- How many potential perpetrators were present?
- Does the bloodstain evidence support or refute witness statements?
What happens to the shape of the blood stain as the angle of impact gets lower and lower?
in shape with no tail or buildup of blood. What happens to the shape of the blood drop as the angle of impact gets/becomes smaller? As the angle of impact becomes smaller, the stain becomes elongated in shape, and longer. tails will appear.
Why is angle of impact important?
The direction of travel for multiple bloodstains in a pattern that combined with the angle of impact determinations, is used to find the location of the blood source that was impacted to create the pattern (Fig. 6). Surface effects on bloodstain appearance are very important.
What can blood spatter evidence tell you?
Based on the varying sizes and shapes of the blood drops, investigators can often tell what type of weapon caused the spatter, determine the general area where the attack occurred, and track the positions of the victim. “Oftentimes blood spatter analysis is used to test an alibi, such as self-defense,” Johnson says.
How Does height affect blood spatter?
The height from which the blood falls will affect the size of the stain, with greater heights tending to result in larger bloodstains. This type of bloodstain is the result of a forceful impact between an object and wet blood, causing the blood to break into smaller droplets.
What type of evidence is blood?
Examples of physical evidence include a document, a hair, fibers, fingerprints, soil, and blood.
What are the 2 main types of evidence?
There are two types of evidence — direct and circumstantial. Direct evidence usually is that which speaks for itself: eyewitness accounts, a confession, or a weapon.
What are the 5 types of evidence?
And even some evidence that is not admissible on its own may be admissible in conjunction with other types of evidence.
- Analogical Evidence.
- Anecdotal Evidence.
- Character Evidence.
- Circumstantial Evidence.
- Demonstrative Evidence.
- Digital Evidence.
- Direct Evidence.
- Documentary Evidence.
What are the five rules of evidence?
These five rules are—admissible, authentic, complete, reliable, and believable.
What are the 3 rules of evidence?
There are four Rules of Evidence; Validity, Sufficiency, Authenticity and Currency. The Rules of Evidence are very closely related to the Principles of Assessment and highlight the important factors around evidence collection.
What is the first rule of evidence?
Relevancy is the first rule of evidence. Legally Relevant. = any evidence having a. tendency to make the existence of any fact. that is of consequence more probable or less.
What evidence can be used in court?
Evidence: Definition and Types There are four types evidence by which facts can be proven or disproven at trial which include: Real evidence; Demonstrative evidence; Documentary evidence; and.
What are the 7 types of evidence?
Terms in this set (7)
- Personal Experience. To use an event that happened in your life to explain or support a claim.
- Statistics/Research/Known Facts. To use accurate data to support your claim.
- Hypothetical Situations.
Can photos be used as evidence in court?
Under the “silent witness” theory, photographic evidence is admissible if the process used to produce the photograph is accurate and reputable. Thus, before photographic evidence is used at trial, the trial attorney must consider the purpose of the photographic evidence and the need for expert testimony.
How do you prove intent?
For general intent, the prosecution need only prove that the defendant intended to do the act in question, whereas proving specific intent would require the prosecution to prove that the defendant intended to bring about a specific consequence through his or her actions, or that he or she perform the action with a …
Is intent hard to prove?
Since intent is a mental state, it is one of the most difficult things to prove. There is rarely any direct evidence of a defendant’s intent, as nearly no one who commits a crime willingly admits it. To prove criminal intent, one must rely on circumstantial evidence.
What are the 3 burdens of proof?
The three primary standards of proof are proof beyond a reasonable doubt, preponderance of the evidence and clear and convincing evidence.
What are the 3 types of intent?
The three common-law intents ranked in order of culpability are malice aforethought, specific intent, and general intent.